Apparatus for connecting metallic strips



Sept 2 1947- p. N. cooLl-:Y 2,426,670 v APPARATUS FOR- CONNECTING' METALLIC STRIPS Filed Dec. 19, 1945 liwefda: m// /V (anni Patented Sept. 2, v1947 APPARATUS Fon Davia N. coley, Gary, Ina.

' Application December 19, 1945, Serial No. 635,929 I Y' 13 Claims. (01.164-109) This invention relates to an improved manner of connecting metallic strips together for continuous pickling or annealing and more particularly to the vpunch and die used for stamping out the interconnecting tongue or stitch portions.

The generally accepted method of joining the ends of strip metal so that it can be continuously annealed, pickled or treated is to overlap the two ends and cut a plurality of coincidental tongues through the superposed strips, relatively move the two superposed strips lengthwise and then bend the tongues'downwardly so that the lower tongue engages the upper strip and the upper tongue engages the lower tongue. The punches and dies heretofore used for striking out the tongues or stitches became dull very quickly causing the metal to tear or rupture, thereby preventing the relative shifting of the sheets prior to bending the tongues down. Moreover, the use of such punches and dies has been limited to one thickness of sheet metal. While attempts have been made to compensate for this and permit their use on a variety of thicknesses by increasing or decreasing the stroke of the punch, there is a tendency to tear the metal at the base of the tongue and cause failure of the connection.

It is accordingly an object of the present invention to provide a stitching apparatus that is simple and dependable in use. A

It is another object to provide a stitching apparatus that will accommodate a wide variety of thicknessesI without adjustment of the parts thereof.

It is a further object to prevent sticking together of the metal strips after being punched,

so they can be easily shifted relative to Aeach` other prior to bending the tongues down to lock the strips together. A. j The foregoing and further objects will be apparent from the specification and drawing, wherein:

Figure 1 is a plan view of a die; l Figure 2 is an isometric view of a punch;

Figure 3 is a sectional elevation showing the' die and punch with superposed thin sheets therebetween in position of stitching;

Figure 4 is a similar view showing the punch at the upper end of the punching stroke;

Figure 5 is a view similar-to Figure 4, but showing materially thicker superposed sheets;

Figure 6 is a partial section of the rolls for bending down the struck out tongues to lock the sheets together; and 4 Figure 7 is a plan View of the struck out tongues after being bent down by the rolls of Figure 6.

A plurality of spaceddie.

tained in a suitablelfame'and extend.acro's's1the^f width ofv the superposed ends S and Sosheet j Directly .fbefy neath the die members 2 are: a plurality. of-vA punches 4 adapted to be. simultaneously opeiated-xv material to be stitched together.

by suitable cranks orrcams (not shown).

The die openings 2* and the punches! arev gen-f l erally rectangular in shape with onesidein the form of an outwardly extending triangles ,-VSuch.- shape will hereinafter-be kreferred 'to asTa-'frecf-'i' tangular polygon. The sides Ii Vand the sloping sides 8 ofthe die and the corresponding sides I0 and I2 of the punch are sharp and adapted to cut metal strip received therebetween to cut out the stitches or tongues. The heel portion Il of the die and the corresponding portion I6 of the punch are rounded o so that metal compressed therebetween will not be cut.

In accordance with the teachings of the pres.- ent invention, the sides L0 of the punch are somewhat shorter than the sides B oi.' the die. Thus whenthe punch is inserted inthe die, the full extent of its stroke as indicated by the point 26, with the edges I2 of the punch in close proximity to the edges 840i the die,4 a space 24 is providedbetween the rounded oil? heel I4 of the die and the heel I6 of the punch. This-space 24 should be about equal to the combined thicknesses of the thickest sheets to be stitchedthereby. It is notedlthat the point 26 is always the same since the stroke of the punch need not be changed in order to accommodate various gauge sheets. At the point of maximum separation, a'.

space 20 is provided between the die and punch, which is equal to the thickness of the thickest sheets to be punched plus thel stroke of the punch., This permits a wide range of sheet gauges to be stitched without changing or adjusting the stroke of the punch. Figure 4 shows the punching` operation on thin gauge sheets S, S', and Figure 5 shows the operation on thicker gauge sheets S. ,It is understood that sheets of heavier gauge whose combined thickness does not exceed the distance 24 between the die and the punch may be punched therebetween. Thesheets may tear relative to the other and the tongues 2v2 are bent embers 2 arevgcon-A" 1:1. Vmanafrattus for *connecting imetallic sheets;

in'iluclirrgifa. pro'iiled die fand punch, jsai'd Fdie :and ispunchf "ing lprovided with 'heel 'creer-@inca .'-sagid the fouter 'limit sides and endsv thereof and non-'cuttin'g'heel surfaces, the sides of `said die andpunch being vslight- 1y ared outwardly from the lheel vsurfaces and the heel Vsurfaces *being substantially yrior'r'nel to :my inYertifon, es ldefineg lin the aiipen'ded the 'longitudinal lcenterline of Hsuperposed Ysheets to'be 'punched byy the 'die a'ndfpun'ch, the clear- "ancebe'tween the heel portions of saidrdie and.V punch when the punch -is ajtrthe outer `limit rof 'itstrayel `heing `equal to the combined thickness of the thickest'pair of sheets to be punched plus ltheiength Cif-travel of said punch and When said l punch is "at the inner limit of lits-travel said clear- 1' ance beingequal to thefcombined thickness fof :the

Y less "of 'the thickest sheets 1to`I`bei-pun'ched therevbetween@his ithefstroke :o'f 'theip'unch 'ffBein'g-l-equal fJ-to ,"#the fconibined thickness `Yof the 1nnpparams furfpuncnirig `@uns in' afpair pf l fsuperprosed metallic `vv`sheets :prior "to relatively Imoving'the 'punched sheets 'lengthwise `and thenV yrolling down the ftabs 5to A lock the sheets: together pun'ch j'andridie having cuttingsufaces 'at `the comprising ffa'di'er and `3a. reciprocable punch, saidl pparatus Yfor connecting lmetallic sheets] 1 sheets tohe punched 'therebe- DAVIDT 'Nfc'oolEm .REFERENCES 'crm-1D The following references-are of record inithe le of thispatent:A

UNrrED :STATES .rPAfrErI'rs'V 

